A Particle Is Moving At $0.86 c$ by What Magnitude Percentage Is the Newtonian Expression for Magnitude

Multiple Choice

A particle is moving at $0.86 c$ . By what magnitude percentage is the Newtonian expression for momentum in error? (The percentage error is the difference between the erroneous and correct expressions, relative the correct one) .

A) $49 \%$
B) $62 \%$
C) $55 \%$
D) $40 \%$