Based on the construction, the incorrect statement is in option d
4. 2 * ∠ ABC = ∠ DBC
How to find the incorrect statement
The construction shown angle bisection of angle ABC, in to angle ABD and anlage DBC.
In other words, the construction produced; ∠ ABD = ∠ DBC from ∠ ABC. Such that
∠ ABC = ∠ ABD + ∠ DBC
Examining the options, we can see that
1. ∠ ABD = ∠ DBC (this is correct)
2. 1/2 * ∠ ABC = ∠ ABD (this is correct)
3. 2 * ∠ DBC = ∠ ABC (this is correct)
4. 2 * ∠ ABC = ∠ CBD
the incorrect option is in option D.
Since angle ABC = 2 * CBD, not the other way round.
The complete question is attached