please done just give me the answer but explain how you found out... thank you... (the topic is functions and transformation

15. The graph of a function y = f(x) is contained completely in the fourth quadrant. Copy and complete each statement. a) If y = f(x) is transformed to y = -f(x), it will be in quadrant . b) If y = f(x) is transformed to y = f(-x), it will be in quadrant . c) If y = f(x) is transformed to y = 4f(x), it will be in quadrant d) If y = f(x) is transformed to y = f(_x), it will be in quadrant