What is the correct sequence of the above nuclear fuels in order of increasing half life?

Question

Consider the following nuclear fuels:

1. Pu²³⁹                 

2. U²³⁵

3. U²³³

4. Th²³²

What is the correct sequence of the above nuclear fuels in order of increasing half life?

a. 1-2-3-4                     b. 1-3-2-4

c. 2-4-3-1                     d. 4-1-2-3