The right option is; orbital period
T stands for orbital period.
Orbital period is the time a certain astronomical object such as planets takes to complete one orbit (360° revolution) around another object such as sun or stars. Orbital period is expressed in different units of time, usually in years, days or hours.
Transcription is important to genetic information. If there is an error during the transcription process, the DNA copies would not be accurate, causing the proteins to be improperly assembled, or not assembled at all.
Bibliography is essential in determining its content. I hope this helped
