Propose structures for compounds that fit the following ¹H NMR data:

(a) C₄H₆Cl₂ 

2.18 δ (3 H, singlet)

4.16 δ (2 H, doublet, J = 7 Hz)

5.71 δ (1 H, triplet, I = 7 Hz)

(b) C₁₀H₁₄

1.30 δ (9 H, singlet)

7.30 δ (5 H, singlet)

(c) C₄H₇BrO

2.11 δ (3 H, singlet)

3.52 δ (2 H, triplet, J = 6 Hz)

4.40 δ (2 H, triplet, J = 6 Hz)

(d) C₉H₁₁Br

2.15 δ (2 H, quintet, J = 7 Hz)

2.75 δ (S (2 H, triplet, J = 7 Hz)

3.38 δ (2 H, triplet, J = 7 Hz)

7.22 δ (5 H, singlet)