A neuron is receiving two simultaneous inputs, one of which is $-10mV.$ If the cells $RMP$ is $-70mV$ and threshold is $-60mV,$ what is the minimum value of the other input that would cause the neuron to generate an action potential?

$-20mV$

$+20mV$

$-10mV$

$+10mV$

$+30mV$