Answer:
The correct option is D. the students were sent a letter of acceptance by the science camp.
Step-by-step explanation:
Option A cannot be correct because a letter of acceptance will not be sent to the science camp. Instead, the science camp sends the acceptance letters to the students.
Option B cannot be true because the sentence structure is not correct.
Option C cannot be true because a letter of acceptance will not be received by the science camp.
Option D correctly indicates the sending of the letter of acceptance to the students by the science camp.