Answer: B. I love to eat chocolate covered pretzels.
Explanation: A hyphen is a punctuation mark with various uses in english, like separate syllables and join words. In the given sentences, the one that needs a hyphen is option b, "I love to eat chocolate covered pretzels", it should be: "I love to eat chocolate-covered pretzels, without the hyphen we can't tell if they are referring to chocolate pretzels that are covered, of pretzels that are covered with chocolate.
D. They are all bad people.
The correct answer is research