Using the $Pb-Sn$ phase diagram below answer the following questions.

a$)$ Fill in the blanks at right with the names for the line types and which phases are present in the phase fields. $(1$ mark each$).$ Phase fields $($letters in square boxes$)$ and lines $($#$\text{'}$s in black circles$)$ have been labeled on the phase diagram.

Lines $1$ each

Phase Fields $[1]$ each

A$.$

B

C$.$