A: Skin
B: Hypodermis - click on the bottom square and you can see the big white blobs of the adipose tissue - the skin does not contain adipose tissue, so this had to be the hypodermis.
C: Skeletal muscle - you see cross sections of red cylindric cells whose nuclei are located only on the periphery.

Click on the top square:
a1: Epidermis
a2: Dermis
1: Hair follicle
2: Hair shaft