Option A - incorrect
It uses a plural pronoun 'they' to replace the singular subject 'the construction company.' The adjective 'less' does not agree with the countable noun bricks.
Option B - incorrect
This has the same as option A. The adjective 'less' does not agree with the countable noun 'bricks.' Also, the noun 'realization' cannot be used as a modifier.
Option C - incorrect
The phrase used 'the realization of' changes the meaning of the sentence.
Option D - incorrect
The subject 'construction company' is singular. So using a plural pronoun is wrong. We need a singular pronoun 'it.'
Option E - correct
This is correct as it uses the correct pronoun 'it' and the modifier 'realized.' It also uses the adjective 'fewer' to qualify the noun 'bricks.'