How does one denote stress in phonetic transcription?

In phonetic transcription, stress is indicated by placing a high vertical line, known as a primary stress marker, before the syllable that is stressed. This notation helps to clarify which syllable receives the most emphasis in a word, which is crucial for accurate pronunciation and understanding. For example, in the word 'photograph' [ˈfoʊtəˌgræf], the primary stress is placed before the first syllable 'pho', signaling to the reader that this syllable is pronounced with greater emphasis compared to the others.

The other options do not conform to standard phonetic notation used in linguistic studies. A low diagonal line and a tilde are not used to denote stress in phonetic transcription. While bold fonts can visually indicate stress in some types of written exercises, they do not represent a formal standard in phonetic transcription. Therefore, the high vertical line is the accepted method for marking primary stress in phonetic transcriptions.