The correct answer would be option C: "intruding", this is due to the fact that snooping is like prying into someone's life without invitation, and intruding is looking intensely at something without someone's explicit invitation with the purpose of criticizing, not just simple curiosity which would be looking or with a non harmful purpose which would be searching.
The overall tone of Mrs. Hale's dialogue is negative. She does not want the men in her kitchen. This is one way which intruding is the answer because she sees the men as intruders. There is nothing to indicate the men are searching for something. Peering has the negative connotation; however, peering usually indicates the person is not directly looking at something or rather trying to secretly look. Substituting the word "looking" is not enough. It doesn't contain the negative connotation that the rest of Mrs. Hale's dialogue indicates.
Kelvin is waiting for James. it is from Kelvin's perspective... he is clearly worried about someone who is going to turn up. James is the only person who is named.