Consider the following grammar:

A → 0 B | 1 C | λ
B → 0 A | 1 D
C → 0 D | 1 A
D → 0 C | 1 B

Which one of the following strings CANNOT be derived from A?

101
  • 1100
  • 001010
  • 1111

Try to build a complete derivation with pencil and paper for each string.

Each derivation must start with the non-terminal A.