Define the following propositions: s: a person is a senior
y: a person is at least 17 years of age
p: a person is allowed to park in the school parking lot

Express each of the following English sentences with a logical expression:

a. A person is allowed to park in the school parking lot only if they are a senior and at least seventeen years of age.
b. A person can park in the school parking lot if they are a senior or at least seventeen years of age.
c. Being 17 years of age is a necessary condition for being able to park in the school parking lot.
d. A person can park in the school parking lot if and only if the person is a senior and at least 17 years of age.
e. Being able to park in the school parking lot implies that the person is either a senior or at least 17 years old.