ANSWER
The greatest common factor is 1.
EXPLANATION.
The given expressions are
[tex]3 {c}^{3} {t}^{3} = 3 \times {c}^{3} \times {t}^{3}[/tex]
and
[tex]4 = {2}^{2} [/tex]
The greatest common factor is the product of least powers of the common factors of the two expressions.
Since the two expressions are relatively prime, their greatest common factor is 1.
