please help with each question

Which alkane has the lowest boiling point? (Hint: Intermolecular attraction decreases with branching.) (A) (B) (C) (D) Which correctly depicts the displacement of bromide by hydroxide? (A) (B) (C) \( \mathrm { HO } ^ { - } \longdiv { \mathrm { Br } - \mathrm { CH } _ { 3 } } \) (D) Hint: Jh:s is indicative / of a corbon y l 3. An unknown compound/shows an intense absorption near 1700cm1 in the ir and gives the following nm r spectrum: 81.1 doublet, 6H;8 2. 1, singlet, 3H; and 8 2.3-2.8, broad multiplet, 1H. Which structare is consistent with the above data? (1) (CH3)2CHOCH3 (3) CH2CH2CH2OCH3 (2) (CH3)2CHCCH2 (4) CH2CH2CH2CCH3