Name two intersecting lines in the attached image

Question

Could anyone help me understand the answer of this question ?
This question is asked in 6th grade as part of the Indian CBSE curriculum.

I think the answer should be AB (BA) and CD (DC).
Are OA, OC, OB, OD all valid answers ? If yes, why ?

Thanks!

Answer 1

When we have 2 Points $X$ & $Y$ :
$\overline{XY}$ : It is the line Segment between $X$ & $Y$ , not going Beyond those 2 Points.
$\overrightarrow{XY}$ : It is the ray Starting @ $X$ & moving towards $Y$ & going Beyond.
$\overleftrightarrow{XY}$ : It is the line between $X$ & $Y$ & going Beyond in Both Directions.

At the level of some textbooks , $XY$ is used for all these Cases , without Distinction , which makes it highly ambiguous & that should be avoided.

In OP Case , (38a) Points are $A$ , $B$ , $C$ , $D$ , $O$ , where 2 can be selected.

Moving to (38b) , there are 2 lines here :

$\overleftrightarrow{AB}$ , $\overleftrightarrow{BA}$ , $\overleftrightarrow{AO}$ , $\overleftrightarrow{OA}$ , $\overleftrightarrow{BO}$ , $\overleftrightarrow{OB}$ : (All Same : Choose 1)

$\overleftrightarrow{CD}$ , $\overleftrightarrow{DC}$ , $\overleftrightarrow{CO}$ , $\overleftrightarrow{OC}$ , $\overleftrightarrow{DO}$ , $\overleftrightarrow{OD}$ : (All Same : Choose 1)

Some references :

https://smartclass4kids.com/point-lines-line-segments-and-rays/

https://yup.com/math-resources/lines-line-segments-rays/

https://www.turito.com/learn/math/line-segment