domain is the set of numbers you can use for x
log_4(x+3)=y means
I mean it translates to
4^y=x+3
remember that x^m≥0 for all real values of x and m
it actually can equal 0 only when x=0 or when x is very small
so
therfor since 4^y>0, x+3>0 as well
solving we get
x>-3
all rea lnumbers greater than -3
2nd option