The job of best man is at all arduous

[Komon]

Test No. incompl/advan-30 "Letter Writing (2)", question 7

In fact you could not possibly say that the job of best man is at all ..........

(a) arduous
(b) articulate
(c) ardent
(d) arduously

Test No. incompl/advan-30 "Letter Writing (2)", answer 7

In fact you could not possibly say that the job of best man is at all arduous.

Correct answer: (a) arduous

Your answer was: incorrect
In fact you could not possibly say that the job of best man is at all articulate.
_________________________

The meaning of this sentence is not clear for me. I wonder how you use the word "arduous" usually.

[Mister Micawber]

.
Arduous means hard, difficult. It is a more formal word, but here it is used ironically or as hyperbole for the purpose of humour, as of course being best man at a wedding is quite fun and easy.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber