Katie's property is located on a hillside. According to a flood insurance rate map $($FIRM$),$ the upper portion of Katie's property is higher than the elevation that has a $1$ percent chance of flooding in any given year. The technical term for the elevation at which there is exactly a $1$ percent chance of flooding is commonly referred to by its initials,

$($Search Chapter $1).$

a$.$ BFE.

b$.$ FIRM.

c$.$ NFIP.

d$.$ FHA.