Two Boxes Are Connected to Each Other by a String

Multiple Choice

Two boxes are connected to each other by a string as shown in the figure. The 10-N box slides without friction on the horizontal table surface. The pulley is ideal and the string has negligible mass. What is true about the tension T in the string?

A) T<30 N
B) T=10 N
C) T=20 N
D) T>30 N
E) T=30 N