Please help me!!! Will give the brainlyest!!!!

Hey there!!
How do we find the determinant ?
Ans = ad - bc : determinant
In the given matrix ,
a = -5
b = 1
c = 1
d = 4
Determinant = ( -5 ) ( 4 ) - ( 1 ) ( 1 )
... - 20 - 1
... -21
Option ( c )
Hope it helps!