worried about the validity of the contract mean how to form valid contract??

Dear Sir,

Robert is a very successful real property developer and wants to sell his house worth
RM500,000 to one of his employees, Jack. Robert would like to sell his house to Jack for
only RM1,000 due to his excellence performance in the company. However, Robert is
worried about the validity of the contract between them and seeks for your advice on this
matter.

I am confusing the question is asking us how to form a valid contract or asking us what are factors will affect the validity of the contract??

if how to form a valid contract – I will apply all the elements of a contract are proposal or offer, acceptance, consideration, intention to create legal relations, capacity, certainty, consent, and legality and explain each of the them

If only factors I will only apply,

This is followed by Section 14 where it states consent is not ‘free’ when it is caused by
the following elements:
– Coercion – S 15 (voidable)
– Undue influence – S 16 (voidable)
– Fraud – S 17 – (voidable)
– Misrepresentation – S 18 – (voidable)
– Mistake – S 21 (void) & S 23 (valid)