Adouble circulatory system is composed of a circuit and a(n) circuit

A double circulatory system is composed of a PULMONARY circuit and a(n) SYSTEMIC circuit

Pulmonary circulation means where blood goes to lungs to get purified and exchange gases, i.e. CO2 is released into the lungs and oxygen is taken into the blood.

Systemic circulation is between heart and entire body, where oxygen is supplied to every cell of the body and CO2 is absorbed.

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.