Let σ = {0,1} and let B be the collection of strings that contain at least one 1 in their second half. In other words, B = {uv | u ∈ σ∗, v ∈ σ∗1σ∗ and |u| ≥ |v|}.

a. Give a PDA that recognizes B.
b. PDA for the complement of B.
c. Regular expression for B.
d. Context-free grammar for B.