Question $2$: Identifying a function's time and space efficiency

An Al 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 isPrime$($number $n)$

for i from $2$ to square root of $n$

rounded down inclusive

if nmodi is $0$

return false

return true

Function B

function isPrime$($number $n)$

factors $=$ generated array of numbers

from $2$ to $n-1$ inclusive

for $i$ in factors:

if nmodi is not equal to $0$

remove i from factors

if factors is not empty

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.

Function $A$ is the most efficient function

Function $B$ is the most efficient function

Function $C$ is the most efficient function

All three functions are the same in terms of efficiency

Explanation

In $2-3+$ complete sentences, please provide your reasoning for your above selection.