Confused

in questions 19–20, read each sentence, and decide whether the (words in brackets) contains a mistake. if so, identify the best way to correct or improve the sentence by choosing the appropriate suggestion from the answer choices. if the underlined portion requires no correction or improvement, choose no improvement or correction is required
19.
(it is fortunate that you were able) to fix the faucet because we need to use the water.

a) it was fortunate that you were able

b) b- it is fortunate that you will have been able

c) c -it were fortunate that you were able

d) d- it is being fortunate that you are able

e) e -no improvement or correction is required.

20.
if you are going to the concert, (you should buy tickets in advance).

a) advance tickets should be bought

b) tickets should be bought in advance

c) tickets should have been bought in advance

d) should buy advance tickets

e) no improvement or correction is required.