During embryonic development,which germ layer gives rise to the endoskeleton and muscles?

$A$: The first sign of a growing foetus may be noticed by listening to the heart sound through the stethoscope.
$R$: By the end of the second month of pregnancy,the foetus develops limbs and digits.

Which of the following statements is true regarding cells during cleavage?

Select the correct pairs of germ layers and their derivatives from the following; and choose the correct option given below.

Germ layer	Derivatives
$a$. Mesoderm	All types of muscles of body
$b$. Ectoderm	Iris Muscles and Ciliary Muscles
$c$. Endoderm	Lining of Middle ear
$d$. Ectoderm	Adrenal cortex and Medulla
$e$. Mesoderm	Sclera and Choroid layer of eye

The first germinal layer formed in the human embryo is . . . . . . .

In a urine analysis,the presence of which of the following indicates pregnancy?