Design a program in Python and select features from list A and list B, given the following constraints:
List A: [a, b, c, d]
List B: [1, 2, 3, 4]
Constraints: 
Select 2 features from list A, and 
select 1 feature from list B
features = [a, c, 2] # Selecting a, c from list A and 2 from list B.