In the context of Porter's Five Forces Model, which is the difference between buyer and supplier power?

a$.$ Buyer power is high when customers have many choices, whereas supplier power is high when customers have fewer options.

b$.$ Buyer power is low when customers have many choices, whereas supplier power is low when customers have fewer options.

c$.$ Buyer power is low when customers have many options, whereas supplier power is low when customers have more choices.

d$.$ Buyer power is high when customers have few choices, whereas supplier power is high when customers have more options.