The Battle of Trafalgar was a pivotal naval battle

Eliminate A/B for using "amount". "Number" is used for things that can be counted, while "amount" is used for things that cannot be counted. "Ships" can be counted. 10 ships, 20 ships, a gazillion ships, etc. Thus, "amount" should not be used with "ships".

(D) can be eliminated for pairing plural verb "were" with singular subject "English fleet".

(E) can be eliminated for using "its" making the sentence non-sensical.
"its" should refer to "English ships" not "number of English ships". This error is rectified in (C), which is the correct choice.
Also, "the number of" in (E) depicts an actual number, say 100, to use fewer with an actual number does not make any sense. You don't say, 100 is fewer than 120. We say, 100 is less than 120. That's one more reason to dump (E).
Posted from my mobile device

A) the amount of English ships was less than their Franco-Spanish opponents, but the English fleet were victorious on account of their brilliant
"amount of" is wrong ,should be number if .fleet and were,SVA error

B) the amount of English ships was less than their Franco-Spanish opponents, but the English fleet was victorious on account of its brilliant
same as A, "amount "is wrong

C) the English ships numbered fewer than their Franco-Spanish opponents, but the English fleet was victorious on account of its brilliant
looks good

D) the English ships numbered fewer than their Franco-Spanish opponents, but the English fleet were victorious on account of their brilliant
fleet,were,their SVA error

E) the number of English ships was fewer than its Franco-Spanish opponents, but the English fleet was victorious on account of its brilliant
"its" is referring back to number of english ships. english ships had the opponents not the number
IMO C

C is the answer.

Amount cannot be used for ships, so A and B is out. SV error in D. E has comparison issues, comparing number with its opponents

Posted from my mobile device

What's the meaning of the below sentence

the English ships numbered fewer than english ship's Franco-Spanish opponents, but the English fleet was victorious on account of its brilliant???

Answer is between C and E ..But neither option looks good

Posted from my mobile device

Option C is also incorrect. “Opponents” should be a possessive “opponent’s”

Posted from my mobile device

Vatsal7794 The meaning of the sentence above is: English ships were fewer than the Franco-spanish ships. But, the English fleet won because of its brilliant tactics and morale. Here, "on account of" stands for "because of". So, (C) makes sense and is correct. Hope it helps.

Jazzutds Actually here the author seems to be putting English ships and Franco-Spanish ships as "opponents". So, "franco-spanish opponents" here stands for "franco-spanish ships". Hence, the comparison is correct. Hope it helps.