Answer:
The correct option is B. The length of OB' is 3 units.
Step-by-step explanation:
The rule of dilation is Dā,ā. It means dilation by scale factor 4 with center of dilation is origin.
[tex]\text{Scale factor}=\frac{\text{Distance between center and any point of the image}}{\text{Distance between center and corresponding point of the Preimage}}[/tex]
[tex]\text{Scale factor}=\frac{OB'}{OB}[/tex]
[tex]4=\frac{OB'}{\frac{3}{4}}[/tex]
[tex]4\times \frac{3}{4}=OB'[/tex]
[tex]3=OB'[/tex]
The length of OB' is 3 units. Therefore the correct option is option is B.
