A block of mass 2M is attached to a massless spring with spring constant k. This block is connected to two other blocks of masses M and 2M using two massless pulleys and strings. The accelerations of the blocks are a, a and a3 as shown in the figure. the system is released from rest with the spring in its unstretched state. The maximum extension of the spring is xo. Which of the following option(s) is/are correct? [g is the acceleration due to gravity. neglect friction] A. a-aa-a3 B. At an extension of of the spring, the magnitude of acceleration of the block 3g 10 connected to the spring is C. Xo 4Mg k Xo spring is 3g M 5k ooooooo 2M a a M Xo D. When spring achieves an extension of for the first time, the speed of the block connected to the 2M a3