B. a smaller speed and a longer period.
[tex]F_c = m \frac{v^2}{r} = m \frac{4 \pi^2 r}{T^2}[/tex]
[tex]F_c \propto 1/r[/tex],
[tex]F_c \propto 1/T^2[/tex],
[tex]F_c \propto v^2[/tex].
Therefore, increasing the radius decreases [tex]F_c[/tex]
Deceasing [tex]F_c[/tex] increases the period.
Decreasing [tex]F_c[/tex] decreases the speed.