Pick Closest Number To X And Display Corresponding Value

i have a sample of data in a column,

.....A
A1 20.5
A2 -20.1
A3 19.99
A4 -20.12
A5 20.15
A6 -20.15

In other columns of the same book i have the values;

...............C ..................D ....................E
................x ................CDF ...............1-CDF
1 .......-20.782066 ......0.000302 .......0.999698
2 .......-20.689948 ......0.000311 .......0.999689
3 .......-20.59783 ........0.000321 .......0.999679
4 .........20.505711 ......0.000331 .......0.999669
5 .........20.413593 ......0.000341 .......0.999659
6 .........20.321475 .......0.000352 .......0.999648

how to pick the closest value to any number in A from column C, and then depending on whether its positive or negative, display the corresponding value from D or E.

So if we had -20.77 in col A, it would pick the closest number from col C (In C1) and then display the value from D1. Similarly, if we had +20.4 in col A, it would pick the closest number from col C (C5), and display the corresponding value from E, E5.