Assertion (A): Foetal heart contains mixed blood.
Reason (R): In foetus, pure blood gets mixed with impure blood through the foramen ovale present in the interatrial septum.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.