We don't have to work anything out, just look through the answers. There are no angle measures or angle congruences indicated so none of the similarity theorems that use angles, namely SAS and AA, can be right. That leaves not similar.
If we did want to check SSS similarity we have to check the corresponding ratios are equal. Compare for example the ratio of the smallest sides to the ratio of the medium sides,
62/7 to 81/8
We can see those aren't equal because 8×62 is even and 7×81 is odd.
