Given the task definition and input, reply with output. In this task, you need to provide the correct option for a given problem from the provided options.

Problem: 120 kg of an alloy a is mixed with 180 kg of alloy b . if alloy a has lead and tin in the ratio 2 : 3 and alloy b has tin and copper in the ratio 3 : 5 , then the amount of tin in the new alloy is ? 
Options: a ) 100.6 kg , b ) 120.3 kg , c ) 139.5 kg , d ) 140.8 kg , e ) 114.5 kg

c