a) cleaned his living room. b) had his bathroom retiled. c) repainted his kitchen. d) tidied his bedroom.

My Answer: (b) is the odd one out because had is included as a causative verb, meaning someone else did this job for Martin. The other items only use the past participle of the verb (cleaned/repainted/tidied) because Martin did these jobs himself.

Could you please advise if this is correct and a good explanation? I am working on the pre-interview tasks for my CELTA application.

Many Thanks.