First:

Past simple Vs Past perfect:

We need to use past perfect if there are two actions in the past. There are only one action in this sentence. So we need to use past simple.

We can eliminate B and C.

Second:

Even though.........but: is not correct because both of them express contrast. We should not use both of them in the same sentence.

Example:

Even though he was ill, he worked the whole day. --Correct.

Even though he was ill, but he worked the whole day. Incorrect because there is not independent clause. But introduces coordinate clause.

We can eliminate E.

Third:

if we use "--ING, someting", this something MUST have a NOUN/PRONOUN that can be modified by the --ING. The option D does not have that NOUN/PRONOUN.

Eliminate the option D.

[spoiler]Answer: A[/spoiler]

Thanks for detailed explanation...

but still i think there needs to be more explanation to cancel out E option.

As far as , independent clause is concerned , it is there in terms of

he quickly built..........