Read Chapter One of the story The Mystery of the Missing Library Books: Chapter One: A New Case

A growing mass of clouds blocked the sun, just as I, Dennis the Detective, entered the library. When I requested the new book about my hero, Sherlock Holmes, the library helper's brow furrowed, and his tense lips formed a line like a ruler.

"I'm afraid that book is no longer available," Victor stated.

I stared in disbelief. Turning, I walked towards the new releases section, but most of the shelves were as empty as overturned buckets. Sandra, my sidekick, was hidden behind her pile of books. She updated me on detective gear, handed me a glass of water, and introduced our next assignment. We would be investigating the missing library books. I looked at Sandra, reluctant to investigate books.

Just then, Victor pulled up a chair and sat down. Sandra introduced him to me as our client. Victor adjusted his glasses, looked down at the ground, and took a deep breath. He explained that library books were disappearing each night, especially new releases. The only people who had keys were the librarians and the library helpers. The librarians were beginning to blame the library helpers for the missing books, thinking that they weren't locking the library doors properly. This obviously didn't sit well with Victor, and one librarian in particular had him worried. Wilma always stayed until the last minute and left without checking anything out. The next day, the books were gone.

I raised my eyebrows and rubbed my hands together in anticipation. I had misjudged the situation, thinking it would be easy. Instead, this puzzle would require all of my detective skills.

Why were Wilma's actions suspicious? (2 points)

a
Wilma didn't check any of the books out because she was at the library every day.

b
Wilma had to be taking the books and blaming the library helpers to cover up.

c
Wilma never took any books out because she had big fines on her library card.

d
Wilma stayed late and left without checking out books, so she could be taking them.