Section 120A of the IPC defines criminal conspiracy, and this question asks which statement about it is legally accurate. Each option can be tested against the actual ingredients of the offence.
- The mere agreement between parties is sufficient to constitute the offence if the intended crime is punishable by death or rigorous imprisonment: this reflects the actual position under Section 120A read with Section 120B, ordinarily an overt act in pursuance of the agreement is expected, but where the object of the conspiracy is an offence punishable with death, imprisonment for life, or rigorous imprisonment for a term of two years or more, the agreement itself is sufficient, no further act need be proved.
- It is a substantive offence that is legally barred from being charged in conjunction with other substantive crimes: criminal conspiracy is indeed a substantive offence in itself, but there is no legal bar on charging a person with conspiracy alongside the substantive offence that was the object of that conspiracy, courts routinely try conspiracy charges together with the underlying substantive offences.
- A solitary individual's mere intention to commit a crime, even without an agreement with others, is sufficient for a conviction: conspiracy is inherently an offence of agreement between two or more persons, a single person cannot conspire alone, and mere intention without any meeting of minds with another person does not satisfy the definition in Section 120A at all.
- A minimum of five persons must participate to satisfy the legal definition: Section 120A requires an agreement between two or more persons, there is no requirement of five persons, the offence is complete once at least two persons agree.
Only the first option correctly captures the special rule for serious offences under Section 120A, the remaining options either wrongly bar joint charging, wrongly permit a solitary individual's intention to suffice, or wrongly inflate the minimum number of conspirators required.
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.