Refer to figure.
For this question, advise the take-off field length requirements on CAP 698 Section 3 - MEP1 p.1,2.

An airfield is called as "unbalanced", when a stopway and/or a clearway is available. In this case, the take-off distance must:

• Not exceed TORA
• When multiplied by 1.3, not exceed ASDA
• When multiplied by 1.15, not exceed TODA

If the runway surface is other than dry and paved, apply the factors referred to the figure, when determining the take-off distance.

In this question, the runway is paved and wet, thus, the TODA must be factored down by 1.0, according to the regulations.

Also, the TODA must be factored down by 5% or 1,05, due to the 1% runway upslope.

Therefore, the defactored TODA that could be used to enter the take-off performance graph for a multi-engined piston aeroplane used for Commercial Air Transport, will be: 4230 ÷ 1.15 ÷ 1.0 ÷ 1.05= 3503 ft