Difference between acceptable and considerable

[amna]

Test No. incompl/inter-70 "How to criticize", question 7

I'm afraid to tell you that your standard of work has fallen well below what we think is ..........

(a) considerable
(b) believable
(c) acceptable
(d) available

Test No. incompl/inter-70 "How to criticize", answer 7

I'm afraid to tell you that your standard of work has fallen well below what we think is acceptable.

Correct answer: (c) acceptable
_________________________

both a & c might be correct answers

[Torsten]

No, only acceptable is correct here. Considerable doesn't work because it means sizeable or substantial.
In all of our tests only answer option is correct.

TOEIC listening, photographs: Two people hugging