Read the paragraph and answer question.

“The chocolate analysis must start with the visual aspect. A bar, for instance, has to be uniform, quite flat and bright. A whitish aspect is not a good sign, that means it remained on the shelf and melted,” explains the confectioner.

(Taken from TAM magazine # 38)

GLOSSARY
whitish – esbranquiçado
melted – derretido

The modal verb “must”, in the paragraph, expresses