When an officer of a city entertains doubts concerning the law in any matter before him in his official capacity, and desires the opinion of the city director of law, he shall clearly state to the director of law, in writing, the question upon which the opinion is desired, and thereupon the director of law shall, within a reasonable time, reply orally or in writing to such inquiry. The right conferred upon such officers by this section extends to the legislative authority of the city, and to each board provided for in Title VII of the Revised Code.