Step 1: Recall the list of neighbours with land borders.
India has land borders with Bangladesh, China, Pakistan, Nepal, Myanmar, Bhutan and Afghanistan (through Indian-claimed territory). Sri Lanka and the Maldives are island neighbours.
Step 2: Rank them by length.
Ranked from longest, the order is Bangladesh, China, Pakistan, Nepal, Myanmar, Bhutan.
Step 3: Remove wrong options.
Sri Lanka is removed because there is no land border. China and Pakistan are second and third.
Step 4: Pick the top one.
The top of the ranking is Bangladesh, so option 1.
Final Answer:
Ranking neighbours by border length puts Bangladesh first, so the answer is option 1.
\[ \boxed{\text{Option 1}} \]