The correct option is
C None
From (i), (ii), (iii) and (iv), S, Q and T gets North facing flats.
R and U gets South facing flats. So, P gets South facing flat.
From (ii) and (iii),
S or Q can't be in middle, so it is on either of the corner.
And thus T is in the middle facing North.
And also U is on either of the corners since S is.
Thus, S, T, Q form a row of flats facing North and P, R, U form a row of flats facing South.
To arrive at this result, we have used all the above points.
Thus, no statements should be dispensed.
Hence, option A is correct.