Concept:
India shares land borders with seven distinct nations and maritime borders with several neighbors in the Indian Ocean region. A "common boundary" traditionally refers to direct contiguous land borders.
Step 1:
Let us analyze the land boundaries of India:
• Afghanistan shares a land border with India in the northern region of Jammu and Kashmir (along the Wakhan Corridor, currently Gilgit-Baltistan).
• China shares an extensive land boundary with India across the northern and northeastern borders.
• Myanmar shares a continuous land boundary with India's northeastern states (Arunachal Pradesh, Nagaland, Manipur, Mizoram).
Step 2:
The Maldives is an island nation located southwest of India in the Indian Ocean. It shares a maritime boundary with India (separated by the Eight Degree Channel near Lakshadweep) but does not share any direct *land* or contiguous terrestrial common boundary. Thus, it fits the requirement of the question perfectly.