Which of the following statements are correct?
$A$) $\alpha$-amino acids present in proteins are $L$-amino acids.
$B$) Amino acids contain both $-NH_2$ and $-COOH$ groups.
$C$) The number of amino groups and carboxylic groups is always the same in amino acids.
$D$) Tyrosine was first obtained from cheese.
Choose the correct alternatives from below:

• A
  $A$ and $B$
• B
  $A$, $B$ and $D$
• C
  $B$ and $C$
• D
  $A$, $B$ and $C$