This was a popular question. However, most candidates did not introduce Abu Bakr as the first and rightly guided Caliph. The general performance of candidates that attempted the question was average.
The question requested the candidates to give an account of the contribution of the first caliph, Abu Bakr to in Islam. Thus:

Caliph Abū Bakr b. Abī Quhᾱfa (632 – 634 CE) was the first of the rightly guided Caliph of Islam (Introduction).

• He dispatched Usamah’s expedition which had been planned by the Prophet (S.A.W) against the Byzantines.
• He fought against those who laid false claims to prophethood (riddah wars).
• He enforced the collection of Zakᾱt from those who had threatened withdrawing its payment.
• He expanded the frontiers of Islam.
• He sent an expedition to avenge the murder of the Prophet’s (S.A.W) emissary sent to the Ghassanid prince of Basrah.
• He personally supervised the activities of the state officials including the army.
• He participated actively in all battles fought during the Prophet’s (S.A.W) time.
• Abū Bakr ordered the collection and compilation of the Qur’ān into a book form.
• He also provided the able leadership required to keep the Muslims united.
• Abū Bakr resolved the initial differences that threatened to divide the Anṣār and the Muhājirūn.
• He replicated the leadership style of the Prophet (S.A.W).
• He suffered a great deal of persecution with the Prophet (S.A.W) in Makkah.
• He spent his wealth and energy to propagate Islam.
• He purchased many Muslim slaves from their pagan masters and set them free.
• He was given the title of ‘al-‘Atīq (one who sets slaves free) for setting slaves free.
• He was the first male adult to accept Islam.
• He accompanied the Prophet (S.A.W) during Hijrah to Yathrib in 622 CE.
• He accepted Islam without reservation and was nicknamed Trustworthy (aṣ-Ṣiddīq).
• He was with the Prophet (S.A.W) in Cave Thawr (Q9:40).
• He demonstrated the spirit of an Islamic ruler.
• He dispatched expedition to Syria as ordered by the Prophet (S.A.W).
• He ruled by consultations (Shūrᾱh).
• He demonstrated humility, truthfulness and honesty throughout his tenure.
• He directed the Shūrᾱh to determine who becomes the next Caliph.
• He suggested the name of ‘Umar b. Khaṭṭāb and this was accepted by the Shūrᾱh.
• He made ‘Uthman b. Affān to document the decision of the Shūrᾱh on the next Caliph and this was read out in the mosque in Madīna.