The triangles are congruent by the SAS congruence theorem. By extension, we can also say they are similar using a closely related theorem. Any time there are congruent triangles, they are automatically similar.
This is why the answer is choice C) Similar - SAS
Note how
SB = ET ... which forms the first "S" in "SAS"
angle ESB = angle SET ... which forms the "A" in "SAS"
SE = SE ... which forms the second "S" in "SAS"
this is why SAS works