A $$CPU$$ generally handles an interrupt by executing an interrupt service routine

Normally user programs are prevented from handling $${\rm I}/O$$ directly by $${\rm I}/O$$ instructions in them. For $$CPUs$$ having explicit $${\rm I}/O$$ instructions, such $${\rm I}/O$$ protection is ensured by having the $${\rm I}/O$$ instructions privileged. In a $$CPU$$ with memory mapped $${\rm I}/O$$, there is no explicit $${\rm I}/O$$ instruction. Which one of the following is true for a $$CPU$$ with memory mapped $${\rm I}/O$$ ?

How many $$8$$-bit characters can be transmitted per second over $$9600$$ baud serial communication link using a parity synchronous mode of transmission with one start bit & Eight data bits, two stop bits, and one parity bit

Which one of the following is true for a $$CPU$$ having a single interrupt request line and single interrupt grant line?