Question on Cambridge International economics exam - consumption function

Geuze

Somebody asked me my opinion on what is the answer to this MCQ in the 2014 Cambridge International Advanced Level exam:

I am a bit confused.

The simple version of a consumption function is:

C = f (Y)

C = C(autonomous) + (MPC) (Y)

So the intercept is autonomous consumption, and the slope is the MPC.

In a more advanced version, with taxes and benefits spending added in, the C function becomes:

C = C(autonomous) + MPC (disp Y)

C = C(auto) + MPC (Y + social benefits - direct taxes)

If the UN benefit payment is increased, how will it affect the function?

Economics101

Sorry not to answer your query, but the question as posed is dreadful rubbish. Sure, Consumption is a function of Income, but the labelling of the X-axis as National Income is plain wrong. It should be Personal Disposable Income if anything. And then the question: "If the UN benefit payment is increased, how will it affect the function? " is not very clear. it might affect consumption, but not the function itself.