Hello you!

i took a because all i did was i just divided 24 by 2 = 12
however, i don't think i am right though : )
there is a reason they added option d which looks like there are something missing in the triangle.

explain your answer.

given that triangle abc is transformed two times to get triangle

a"b"c"

first abc is transformed in to a'b'c' as follows:

the coordinates of a are (1,-1) and transformed into a'(-1,1)

similarly b (4,-2) became b'(-4,2) and

c(7,-2) became c'(-7,2)

i.e. (x,y) becomes (-x,-y)

this is nothing but reflection about a point here origin.

thus first transformation is reflection on the origin.

next is exactly shifting 3 units down

source:

1010: 3030

is it i think