Question

skeletal muscle fibers differ from \typical cells\ in that these muscle fibers
lack a plasma membrane.
are very small.
lack mitochondria.
contain endoplasmic reticulum.
have many nuclei.

Explanation:

Typical cells have one nucleus, while skeletal muscle fibers form by fusion of multiple myoblasts, resulting in multinucleated cells. All cells have a plasma membrane; skeletal muscle fibers are large, not small, and have mitochondria (for energy) and endoplasmic reticulum (sarcoplasmic reticulum, a specialized form). Only the multinucleated trait is a unique difference here.

Answer:

have many nuclei.