**Core Concept**
Ganja, also known as cannabis, is a psychoactive substance obtained from the dried flowers, leaves, and stems of the female plants of the genus *Cannabis*. The main psychoactive compound in ganja is tetrahydrocannabinol (THC), which acts on the endocannabinoid system.

**Why the Correct Answer is Right**
Ganja is primarily obtained from the *Cannabis sativa* and *Cannabis indica* species, which are cultivated for their psychoactive and medicinal properties. The dried flowers, leaves, and stems of these plants are harvested, processed, and then smoked, vaporized, or ingested to produce the desired effects. The THC in ganja binds to cannabinoid receptors in the brain, leading to altered perception, mood changes, and other psychoactive effects.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the genus or species of the plant from which ganja is obtained.
**Option B:** This option is incorrect because it does not accurately describe the primary source of ganja.
**Option C:** This option is incorrect because it is not a recognized species of the *Cannabis* genus.

**Clinical Pearl / High-Yield Fact**
The *Cannabis sativa* and *Cannabis indica* species have been used for medicinal and recreational purposes for thousands of years, and their psychoactive compounds have been studied extensively for their potential therapeutic benefits.

**Correct Answer:** C. *Cannabis indica*