All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
Five people among the ten who were given glad tidings of entering Paradise embraced Islam at the hands of Abu Bakr As-Siddeeq, may Allah be pleased with him.
It was also said that they were six people, and they are the following:
‘Uthmaan ibn ‘Affaan, Talhah ibn ‘Ubaydillah, Az-Zubayr ibn Al-'Awwaam, ‘Abdur-Rahmaan ibn ‘Awf, Sa‘d ibn Abi Waqqaas, and Abu ‘Ubaydah ibn Al-Jarraah.
As-Seerah Al-Halabiyyah reads:
"In brief, five people among the ten who were promised Paradise embraced Islam at the hands of Abu Bakr As-Siddeeq; they are:
‘Uthmaan, Talhah ibn ‘Ubaydillah, Az-Zubayr, Sa‘d ibn Abi Waqqaas, ‘Abdur-Rahmaan ibn ‘Awf; and some added a sixth one, who is Abu ‘Ubaydah ibn Al-Jarraah.”
Perhaps this is a quiz question; if this is the case, then please be informed that we do not normally answer these kinds of questions.
Allah knows best.