Question

match each striation band with its composition.
instructions
i band (light band)
a band (dark band)
h zone
actin (thin) filaments only
myosin and actin filaments
myosin (thick) filaments only

Explanation:

The I - band is composed of only actin (thin) filaments. The A - band contains both myosin and actin filaments. The H - zone is the region within the A - band that contains only myosin (thick) filaments.

Answer:

I band (light band) - Actin (thin) filaments only
A band (dark band) - Myosin and actin filaments
H zone - Myosin (thick) filaments only