Step 1: Evaluating the Assertion (A):
Infantry is the primary combat arm of the Army. It is characterized by high mobility on foot, allowing it to cross rugged mountains, dense jungles, swampy areas, and urban ruins where armored vehicles or heavy artillery cannot enter. It operates seamlessly in all weather conditions, day and night. Thus, the assertion is True.
Step 2: Evaluating the Reason (R):
Another key tactical characteristic of an infantry battalion is its self-reliance. It is equipped with organic support weapons (such as mortars, anti-tank missiles, and machine guns) that enable it to defend and hold captured territory even if isolated from external armor or air support. Thus, the reason is also True.
Step 3: Evaluating the Logical Link:
Why is an infantry battalion highly adaptable over all terrain? It is because its basic mode of travel is marching on foot and its weapons are man-portable. The ability to defend and hold ground (R) is its primary functional objective, not the cause of its geographical adaptability (A). Because they are two distinct, correct characteristics without a direct cause-and-effect link, (R) is not the correct explanation of (A). This corresponds to option (B).