Question

Four equal resistors connected across a DC voltage source in either series or parallel will have equal voltage drops across each resistor

Answer 1

if the resistors are the same, then they will always drop the same amount of voltage if they are in either parallel or series

Answer 2

In parallel combination, it will have equal voltage but in series it will only have equal electirc current but not voltage.

Answer 3

ohm's law
voltage drop = current * resistance
V = IR

Kirchoff's current law says 'the current is constant through out the circuit'
Kirchoff's voltage law says 'the sum of all the voltage drops = voltage source'

so if the current is the same, and resistance is the same, then the voltage drop will always be the same. we can see the voltage drop is equal over each resistor in a series circuit by applying ohm's law and kirchoffs current law.

now concerning a parallel circuit, and applying ohm's law and Kirchoffs current law and voltage law, we can also find that voltage drop of each resistor is the same in the parallel circuit.

now if the question is asking, 'does one resistor drop the same voltage as another resistor in either a series or parallel circuit' then the answer is true.
if the question is asking, 'is the voltage drop in a resistor of a series circuit the same drop as a resistor in a parallel circuit' then the answer is false.