The correct answer is B)[tex]a_n=3n+1[/tex]
Writing the sequence numerically, we have 4, 7, 10, ...
This is an arithmetic sequence, since there is a constant, 3, added each time. This gives us the explicit formula
[tex]a_n=4+3(n-1)[/tex]
Using the distributive property, we have
[tex]a_n=4+3*n-3*1
\\
\\a_n=4+3n-3[/tex]
Combining like terms, we have
[tex]a_n=3n+1[/tex]