Answer:
A.
Soon after they hatch, plover chicks can walk on their own; however, they cannot fly for at least a month, making it difficult for them to evade the human onslaught on sunny summer days.
Step-by-step explanation:
This should be the answer, because the punctuation applied here makes more sense to the paragraph. The ; sign indicates a slight change with it's followed by a connector that indicates opposition (however).