Criminal conspiracy under Section 120A is easiest to get right by separating the definition of the offence from the special punishment-linked rule that Section 120A itself carves out, since two of the wrong options attack the definition and one attacks the special rule.
Once the wrong statements about number of conspirators and joint charging are set aside, and the definition is checked against the special punishment-linked rule, the surviving accurate statement is the one about mere agreement being enough for serious offences.
The correct answer is the mere agreement between parties is sufficient to constitute the offence if the intended crime is punishable by death or rigorous imprisonment.
Each of the four options makes a distinct legal claim about criminal conspiracy, so testing each claim against a single, narrow question, is this specifically what Section 120A says or implies, efficiently separates the accurate statement from the three inaccurate ones.
Testing each claim narrowly against the actual text and structure of Section 120A shows that three of the claims either invent a requirement, contradict the definition, or assert a bar that does not exist, while only the claim about serious offences accurately reflects the section.
So the correct answer is the mere agreement between parties is sufficient to constitute the offence if the intended crime is punishable by death or rigorous imprisonment.