∠a is 35° because of vertical angle congruence. ∠b is 55° because one angle is right, so the other two have to add up to 90°, and 90°-35°=55°. ∠c is 110° because it creates a straight angle (180°) with the 70° angle, and 180°-70°=110°.
D. city A is more likely because they have the highest population density just divide the population by number of miles that the city covers and that will show you your density