An AI assistant was asked the following:

"Please create a pseudocode function that can check if a given number n is prime or not, where n $>1."$

The assistant returned the three following functions:

Function A

Function B

Function C

function isPrime$($number n$)$

for i from $2$ to square root of n rounded down inclusive

if n mod i is $0$

return false

return true

function isPrime$($number n$)$

factors $=$ generated array of numbers from $2$ to n$-1$ inclusive

for i in factors:

if n mod i is not equal to $0$

remove i from factors

if factors is not empty

return false

return true

function isPrime$($number n$)$

for i from $1$ to n inclusive

if i $!=1$ and i $!=$ n and n mod i equals $0$

return false

return true

Question:

With respect to memory efficiency and time complexity, please select which function is the most efficient while still being a valid implementation.