Answer:
Calm
Step-by-step explanation:
The third letters in both call and camel are L and M- the first letters the two words do not have in common. The only word choice listed that would appear between these two guide words would be calm, as the third letter in calm is L, and any other third or fourth letters in the remaining answer choices would alphabetically be found after the letter 'm' in "camel".
Camp: Incorrect because letter 'p' is found later in alphabet than 'e' in camel.
Care: Incorrect because 'r' is later in alphabet than 'l' or 'm'
Cast: Incorrect because 's' is later in alphabet than 'm' in camel
Calm: Correct because the third letter 'l' sits between 'l' and 'm' of the two guide words alphabetically.