Select the valid conjecture by the law of syllogism.

given:
if a figure is a square, then the figure is a rectangle.
if a figure is a rectangle, then it is a parallelogram.

a: if a figure is a square, then it is a parallelogram.
b: if a figure is a parallelogram, then it is a rectangle.
c: if a figure is a parallelogram, then it is a square.
d: if a figure is a rectangle, then it is a square.