Answer:
Option A , Chris's
Step-by-step explanation:
Chris is a singular noun and its possessive form can be written as Chris's or Chris' only.
Both the above are correct.
In general possessive form of a noun is either a pronoun or represented as " ' " followed by "s" after the noun in case if it is not ending with "s". In case if it ends with "s" then its possessive form can be either " 's" or only " ' ".
Hence, option A is correct