In general adult health, which of the following readings is widely regarded as a typical normal resting blood pressure level (in mmHg) for a healthy adult?

Introduction / Context:
Blood pressure is one of the most commonly measured health indicators. It is written as two numbers, systolic pressure over diastolic pressure, and measured in millimetres of mercury (mmHg). While exact guidelines can vary slightly between organisations and over time, a reading around 120/80 mmHg is widely taught as a typical normal resting blood pressure for a healthy adult. This question asks you to identify which option best matches that commonly accepted normal value.

Given Data / Assumptions:

• All readings are assumed to be in mmHg and represent systolic/diastolic blood pressure.
• The question seeks a typical normal resting value, not cut offs for high blood pressure.
• We assume an average healthy adult at rest, not someone exercising or under stress.

Concept / Approach:
Traditional teaching and many health education materials describe normal adult blood pressure as approximately 120/80 mmHg. Guidelines may classify lower values as optimal and higher values such as 130/80 or 140/90 as elevated or high, depending on the organisation. Systolic pressure represents the pressure when the heart contracts, and diastolic pressure represents the pressure when the heart relaxes between beats. A reading of 120/80 is therefore a convenient and widely recognised reference value for normal, healthy blood pressure in many general knowledge contexts.

Step-by-Step Solution:
Step 1: Recall that a commonly cited normal blood pressure is about 120/80 mmHg for a healthy adult at rest. Step 2: Recognise that 140/90 is often used as a traditional threshold for hypertension and is not considered normal. Step 3: Note that readings like 135/75 or 130/70 may be acceptable for some individuals but are not the standard textbook example of normal blood pressure. Step 4: Understand that 160/100 is significantly higher than normal and suggests uncontrolled high blood pressure in most guidelines. Step 5: Choose 120/80 as the reading that best matches the widely taught normal adult resting blood pressure.

Verification / Alternative check:
General health booklets, posters in clinics and basic biology textbooks commonly state that a normal blood pressure for adults is around 120/80 mmHg. While more detailed clinical guidelines may provide age specific ranges and emphasise that normal can vary, they still mention 120/80 as the classic reference. For exam purposes, this simple figure is used as the standard example. The other readings listed in the options are either clearly elevated or not the typical one quoted as normal in popular health education.

Why Other Options Are Wrong:
140/90 has traditionally been used as a threshold for diagnosing hypertension and is not considered a normal resting value. 135/75 may be acceptable for some individuals but is not the standard reference given in most basic teaching materials. 130/70 is a relatively low or mid range systolic value and again is not the classic 120/80 figure taught as normal. 160/100 is clearly high and would usually trigger medical evaluation and treatment, not be labelled as normal.

Common Pitfalls:
Learners sometimes think that any value below 140/90 must be normal, but guidelines often distinguish between optimal, normal, high normal and hypertensive ranges. Others may think that only the systolic number matters, ignoring diastolic pressure. To avoid confusion, remember that both numbers are important and that 120/80 is widely used as a simple benchmark for normal adult blood pressure in general knowledge questions. More detailed clinical interpretations are important in medical practice but are usually beyond the scope of basic exams.

Final Answer:
A widely regarded typical normal resting blood pressure level for a healthy adult is 120/80 mmHg.