Final answer:
Spaced or "skip" sheathing is recommended for wood shingles and shakes as it enables good air circulation to help the roofing material dry quickly, preventing rot.
Step-by-step explanation:
The preferable type of roof sheathing to use under wood shingles and shakes to allow them to dry quickly is D. Spaced or "skip" sheathing. Skip sheathing consists of rows of boards laid out across the rafters with gaps between them. This design allows for excellent air circulation beneath the wood shingles or shakes, which is critical for moisture to evaporate and the roofing materials to dry out promptly after wet weather, thereby preventing rot and extending the life of the roof.