Step 1: Identify the recent flashpoint.
Debate in the Maldives has focused on the presence of Indian military personnel operating aircraft/helicopters for humanitarian assistance and medical evacuation.
Step 2: Why this became pivotal.
Domestic politics framed this presence as a sovereignty issue, prompting calls for draw-down and renegotiation—directly straining ties.
Step 3: Eliminate alternatives.
Visa (B), cyber (C), and trade (D) issues exist episodically, but they were not the principal trigger of recent friction.
Step 4: Conclude.
\[
\boxed{\text{Presence of Indian military in the Maldives (Option A) is the key recent factor.}}
\]