Correct option is A
Given:
DDD is the mid-point of BCBCBC.
DL⊥ABDL \perp ABDL⊥AB, and DM⊥ACDM \perp ACDM⊥AC.
DL=DMDL = DMDL=DM.
Concept Used:
If two triangle have one side , hypotenuse and right angle equal to each other,
then both triangles are congruent through RHS congruency.
Solution:

In and
DL = DM
BD = CD ( D is mid point of BC)
So, ( RHS congruency)
thus BL = CM .... (1)
In and
AD = AD (common)
DL = DM
therefore, (RHS congruency)
thus, AL = AM .... (2)
from (1) and (2)
we get AB = AC
Therefore, is an isosceles triangle.