Answer: d) Jake and Leon.
Step-by-step explanation:
According to the described situation, Kendall can sue Jake as well as Leon in most states because Jake did not perform his duty on time and neither he is reliable for the job.Leon as also be sued because he contracted an unprofessional and unreliable person for the job even though he was ill.
Leon should have hired someone who can perform the job well and on time in his absence .This resulted in incomplete installation of troughs and Kendall's work was not done.
Other options are incorrect because Jake and Leon are not individually responsible for work in-completion.Thus, the correct option is option(d).