Read the following sentence and answer the question that follows.

“When Luke arrived at the center he was guarded and didn’t tell the others much about himself.”
Using the denotative and connotative meanings of the word “guarded”, what does this sentence suggest about Luke?

A. He easily made new friends at the center.
B. He had bodyguards walking around the center with him.
C. He was protective of himself and didn’t open up to others.
D. He was happy and comfortable at the center.