Samples of different materials, A and B, have the same mass, but the sample of A is higher in density. Which statement could explain why this is so?

A. The particles that make up material B have more mass than the
particles that make up material A.
B. The particles that make up material A have more mass than the
particles that make up material B.
C. The sample of material A has greater volume than the sample of
material B.
D. The particles that make up material B are more closely packed
together than the particles that make up material A.

The car would move to the right with 150 n of force. the 150 n of force from friction and air resistance slows the car from moving to the right with 300 n of force.

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current

What about pink because im not too fond of red