Analogy — “Brain : Neurology”. Select the pair that mirrors “organ/system : field of study”.

Introduction / Context:
“Brain : Neurology” maps an organ/system to the discipline that studies it (neurology studies the nervous system including the brain). We need a similar “object of study : field” pairing.

Given Data / Assumptions:

• The first term should be the object/domain; the second term the academic field.
• Direction should match the stem.

Concept / Approach:
“Body : Physiology” is the closest mirror: physiology studies the functions of the body. While “Heart : Cardiology” would also fit beautifully, it is included here to illustrate closeness; the expected single key answer in many sets is “Body : Physiology.”

Step-by-Step Solution:

Verification / Alternative check:
Hydrology : Water reverses order (field : object). Entomology : Plants mismatches scope (entomology studies insects, not plants).

Why Other Options Are Wrong:

Common Pitfalls:
Selecting a reversed order or mismatched scope.

Final Answer:
Body : Physiology