Step 1: Note the succession context.
Ayatollah Ali Khamenei had served as Iran's Supreme Leader since 1989. Following his death in March 2026, the Assembly of Experts was tasked with choosing a successor.
Step 2: Identify the chosen successor.
Mojtaba Khamenei, the son of Ali Khamenei, emerged as the new Supreme Leader selected by the Assembly of Experts.
Step 3: Eliminate the distractors.
Ruhollah Khomeini was the first Supreme Leader who died in 1989. Hassan Khomeini is a grandson of Khomeini (a different family). Mohammad Bagher Zolghadr is a military figure who was not appointed Supreme Leader.
\[ \boxed{\text{Mojtaba Khamenei}} \]