Final answer:
The cardinality of 'x' as a day of the week that begins with the letter 'p' is 2.
Step-by-step explanation:
The question asks for the cardinality of 'x' as a day of the week that begins with the letter 'p'. The options given are:
a) 0
b) 1
c) 2
d) 3
To find the cardinality of 'x', we need to count the number of days of the week that begin with the letter 'p'. Since there are two days that fit this criteria, 'Thursday' and 'Sunday', the correct answer is option c) 2.