Identify which one of the following sentences is missing punctuation. Please correct the

Question

error and explain why the correction is necessary.
a. I woke up when the book slipped from my lap and landed on my foot.
b. After the book slid from my lap and landed on my foot I realized that I had fallen asleep.

Answer 1

b.After the book slid from my lap and landed on my foot, I realized that I had fallen asleep.