(1) Zhang may be sentenced to life imprisonment or death penalty, and if he has not entrusted a defender, he should be the object of legal aid. Criminal suspects, defendants and their close relatives have the right to apply for legal aid to defend themselves. Therefore, option A is correct.
② Zhang belongs to one of the four situations that should be defended by legal aid: blind, deaf and dumb; Mental patients who have not completely lost the ability to identify or control their own behavior; Life imprisonment and death penalty; Minors. In the stage of examination and prosecution, if Zhang does not entrust a defender, the procuratorate shall notify the legal aid institution to appoint a lawyer to defend him. Therefore, option B is correct.
(3) If Zhang refuses to entrust a defense lawyer to defend, the court with justifiable reasons shall allow it, and the result must be defended by a defender (entrust a defender or appoint another lawyer). Therefore, the c option is wrong.
(4) From the date of adjournment to the fifteenth day, the defender will prepare the defense, unless Zhang and his defender voluntarily shorten the time. Therefore, the d option is wrong.
To sum up, the correct answer to this question is AB.