Explanation

(c) When loop is entering in the field, magnitude flux linked with the loop increases so induced emf in it $e = Bvl = 0.6 \times 10^{- 2} \times 5 \times 10^{- 2} = 3 \times 10^{- 4}V$ (Negative).
When loop completely enters in the field (after $5\ sec$) flux linked with the loop remains constant, so $e = 0$.
After $15\ sec$, loop begins to exist, linked magnetic flux decreases so induced emf $e = 3 \times 10^{- 4}\ V$ (Positive)