Which one of the following is true?

The translation termination signal is ......... .

$UUU$ codes for:

The triplet codon in genetics is:

Statement $I$: The codon $\text{UAA}$ codes for lysine.
Statement $II$: Genetic code is usually ambiguous.
In the light of the above statements,choose the correct answer from the options given below.

If there are $6$ types of nitrogen bases and $40$ types of amino acids available for protein synthesis,what is the minimum number of nitrogen bases required to form a codon in the genetic code?