The syntax of the sentence follows the Subject+Verb+Object model.
The subject of the sentence is
scientists. The verb
can is a modal auxiliary verb, and
photograph is the main verb.
What can be photographed?
The answer is the object of the sentence. In this case it is:
objects several billion light years away.
How can they be photographed?
With the Hale Telescope
The sentence begins with three prepositional phrases making this part of the object portion of the sentence even though they come before the main noun and the main verb.
You will notice that there is no verbs in the prepositional phrases.
the Hale Telescope in not the main noun or the subject, it needs either a preposition or some type subordinating conjunction in order to signal that it is not the main noun.
From the four choices,
With is the only preposition.
Choices (C) and (D) would make the telescope the subject and main noun. This would cause the sentence to be confusing the second portion of the sentence would have to be reworded to be grammatically correct.
I hope this answers your question.