One out of every thirty personal computer owners in the

D
Fight was between A and D. Thanks to "also" in A, that ended the fight very quickly. There is no mention that they own one and "also" own Mac.

A is the best for me. D seems to state that are the personal computer which owns Macs.

I think we need also here to show the ownership aspect. A is the best here according to me.

OA is A.

OE:

Spot the Error:
Spot #1: Look for descriptive phrases set off by commas in the middle of the sentence.
Spot#2: The presence of underlined verbs indicates that verbs are being tested. Here the sentence has verbs that are underlined. We should examine those first.

Rule and Fix:
Rule: A verb must agree with the noun that is refers to and must use the appropriate tense. Here we have the verb 登wns・which describes takes as its subject 徹ne (out of every thirty)・ Since 登ne・is single the verb must be single. Here owns is the correct number for the verb.

POE:
Given that the verb number is correctly used in the original sentence B should be eliminated.

Chunk and Compare:
Compare A to C. C uses the passive voice. When given a choice choose the active voice over the passive voice. Eliminate C.

Compare A to D. D omits the word also, which alters the meaning of the sentence since part of the intent of the sentence is to emphasize that one in thirty PC owners has a Mac in addition to their PC. Eliminate D.

Compare A to E. E uses the passive voice. Eliminate E.

Reread your choice:
Choose A