Instantaneous power, which is equal to $($current into node $"$a$")*($v$($a$)-$v$($b$)),$ ranges from $-40$ kW to $680$ kW $.$

Which one is the correct statement?

$($ First calculate the active power $($P$).$ It is the cycle average of the instantaneous power. Under sinusoidal steady state conditions, the average of the instantaneous power is the average of the minimum value and the maximum value of the instantaneous power. Then calculate $$ using $P=$VIcos$().$ Finally use $Q=V$in $().$ Caution: use rms values for V and I$)$

a$.$ Within $2$ kVars $,$ the branch reactive power is $640$ kVArs and the rms value of the active component of the branch current is equal to $79\mathrm{.}9/$sqrt$(2)$ ampere.

b$.$ All the other statements are incorrect

c$.$ Within $2$ kVars $,$ the branch reactive power is $165$ kVArs and the rms value of the active component of the branch current is less than $79\mathrm{.}9/$sqrt$(2)$ ampere.

d$.$ Within $2$ kVars $,$ the branch reactive power is $165$ kVArs and the rms value of the active component of the branch current is equal to $79\mathrm{.}9/$sqrt$(2)$ ampere.