Correct option is B
Explanation-
Region A: β-Strand
φ ≈ –120°, ψ ≈ +120°
This is the region where extended β-strand conformations lie, commonly seen in β-sheets.
Region B: Right-handed α-helix
φ ≈ –60°, ψ ≈ –45°
The right-handed α-helix falls here, which is the most common helical structure in proteins.
Region C: Left-handed α-helix
φ ≈ +60°, ψ ≈ +45°
Less common, but this region is where left-handed α-helices appear.
Region D: Collagen triple helix
φ ≈ –60°, ψ ≈ +150°
Collagen has a unique conformation, and its φ-ψ values fall in this distinct region.
Correct Option - B -A - β strand, B - right handed α helix, C - left handed α helix, D - collagen
