Identify the hydrocarbons in the example problem as alkenes', alkynes, cycloalkenes, or cycloalkynes.

$($a$)$ is $a(n)\_\_\_\_$

$($b$)$ is $a(n)\_\_\_\_$

$($c$)$ is $a(n)\_\_\_\_$

$($d$)$ is $a(n)\_\_\_\_\_($this one is tricky.$)$