Please explain the answer. Why (y. y) term is canceled? Do we always evaluate from the first ()? Thank you

Consider the following i-expression ((ay. y) x (iz. z)x)) (ay. y)x). In call by value, the expression can reduce in one step to which of the following? (Ayy)x (az. z) x) X (ay. y)) (ayy)(x x) X (ay. y)) Correct! (x(iz. z) x (ay. y)) (x (Az. z) x)(x)