The rhythm pattern of all sonnets is called

Answer: iambic pentemeter

Iambic pentameter, is the right answer.

Explanation:

Iambic pentameter is a kind of metric line practised in classical English poetry and verse melodrama. The phrase expresses the rhythm, or beat, placed by the terms in that group; rhythm is measured in "feet", small collections of syllables. the term "Iambic" is used to applies to the kind of foot applied, here the iamb, which in English symbolizes an unstressed syllable accompanied by a stressed syllable. "Pentameter" symbolizes a group of five "feet".