Please correct me if my answers to these grammar questions. Thanks in advance.?

Find mistake word from sentence please help me.

But, what if the design would have implicits detrimental overtones?
(A) what if
(B) implicits
(C) detrimental
(D) overtones
Ans (B) implicits
How much people are coming to the interview
A B C
tomorrow morning?
D
(A) How much
(B) people
(C) the
(D) tomorrow morning
Ans (D) tomorrow morning

Bob was sick, so he didn't came
A B C D
to the picnic.
(A) was
(B) so
(C) didn't
(D) came

Ans (D) came

My co-worker ________ go on vacation to Italy last month, but couldn't.
(A) will
(B) is going to
(C) should
(D) was going to
Ans (C) should

Why was Rhonda and Adam late for work
A B C
yesterday morning ?
D
(A) Why
(B) was
(C) work
(D) morning

Ans (D) morning

Can you please type this document important
A B C
for me?
D
(A) Can
(B) type
(C) document important
(D) for

Ans (C) document important