CH3−CH2−CH2−CH2−C||CH2−CH2−CH2−CH3
2-Propylhex-1-ene
Now ,you can gusss the word root.
First just check for parent chain
It should contain double bond
6 carbons⇒word root = hex
Now, give numbering as double bond gets least number.
6CH3−5CH2−4CH2−3CH2−2C||1 CH2−CH2−CH2−CH3
Double bond⇒ Primary suffix ⇒ ene
(c) 2-Propylhex-1-ene ↓
Because three carbons in substituted chain and double bond at C1.