With reference to earthquakes, which of the following statements are correct? A. Earthquakes largely occur along converging plate boundaries only. B. The point of origin of an earthquake within the lithosphere is called the focus or hypocentre. C. The intensity of an earthquake generally decreases with increasing distance from the epicentre. D. The epicentre of an earthquake always lies on the continents only. Select the correct answer using the code given below.

Introduction / Context:
Understanding earthquakes is an important part of geography and earth science. Questions often test knowledge of where earthquakes occur, how they originate, and how their effects vary with distance. This question presents four statements about plate boundaries, the focus (hypocentre), epicentre, and the pattern of intensity, and asks you to determine which ones are correct. It requires careful reading and conceptual clarity, because some statements may be only partly correct or exaggerated.

Given Data / Assumptions:

• Statement A claims that earthquakes largely occur along converging plate boundaries only.
• Statement B defines the focus or hypocentre as the point of origin of an earthquake within the lithosphere.
• Statement C says that intensity decreases with distance from the epicentre.
• Statement D claims that epicentres always lie on continents only.
• The task is to select the option that includes all and only the correct statements.

Concept / Approach:
Statement B is a standard textbook definition: the focus (or hypocentre) is the point inside the Earth where the rupture starts and seismic energy is first released. Directly above this point, on the surface, lies the epicentre. Statement C is broadly correct in practice: as seismic waves travel outward from the epicentre, they spread out and lose energy, so the observed intensity of shaking generally decreases with increasing distance, although local conditions can modify this pattern. Statement A is problematic because it says earthquakes largely occur along converging plate boundaries only, ignoring divergent and transform plate boundaries where many earthquakes also occur, such as along mid ocean ridges and the San Andreas Fault. Thus, A is not acceptable as correct. Statement D is clearly false because many epicentres are located beneath the oceans along mid ocean ridges and oceanic trenches. Therefore, only B and C are correct, corresponding to option C in the code choices.

Step-by-Step Solution:

Verification / Alternative check:
Plate tectonics theory shows seismic belts not only at convergent boundaries but also along mid ocean ridges (divergent) and major transform faults, confirming that earthquakes are not confined to convergent boundaries. Seismology texts define the focus (hypocentre) and epicentre exactly as described in B and in the explanation above. Intensity maps of earthquakes (isoseismal maps) typically show the highest intensities near the epicentre with decreasing values outward, although site effects can cause local anomalies, supporting the general validity of statement C. Records of large submarine earthquakes that generate tsunamis clearly show epicentres in oceanic regions, directly contradicting statement D. These lines of evidence confirm that only B and C are correct.

Why Other Options Are Wrong:

A and B only is wrong because A is not acceptable; earthquakes are also frequent along divergent and transform plate boundaries, not just converging boundaries.

A, B and C is incorrect because it includes statement A, which is misleading as it restricts major seismicity to converging plate boundaries only.

A and D is clearly wrong because both statements A and D are incorrect; D ignores oceanic epicentres altogether.

Common Pitfalls:
Students may be tempted to accept A because many powerful earthquakes occur at convergent boundaries, particularly in subduction zones, and they may not think about divergent and transform boundaries. Another common pitfall is to ignore oceanic earthquakes, focusing only on damaging events on land, which leads to accepting D. To answer correctly, remember that earthquakes occur along all types of plate boundaries, the focus is the origin point inside the Earth, intensity generally decreases with distance from the epicentre, and epicentres can lie under both continents and oceans. Thus, B and C only is the correct combination.

Final Answer:
Therefore, the correct statements are B and C only, corresponding to option C.