mary's pop inn is a portion of her home that she rents to travelers under the auspices of a well$-$known home$-$sharing network platform. According to definitions in Mary's $2022$ homeowners policy, this home$-$sharing host activity

a$.$ is a business

b$.$ is not a business unless it produces more than $$2,000$ of annual revenue

c$.$ is not a business

d$.$ requires mary to carry an umbrella policy