If 4/(1 + 3/x) = 1, then x =
Choose the correct choice from the following answers:	A) 3	B) 1	C) 1 / 3	D) - 1 / 3	E) - 3

Rationale: "the expression 4 / ( 1 + 3 / x ) = 1 should have been equal to something . if 4 / ( 1 + 3 / x ) = 1 = > 4 x / ( x + 3 ) = 1 = > 4 x = x + 3 = > 3 x = 3 = > x = 1 correct option : b"
Answer: B