(A) Incorrect . For the error mentioned above.
(B) Correct . The production of 1979 is compared to the production (or harvest) of 1978.
(C) Incorrect . The production is compared to a year, 1978.
(D) Incorrect . In addition to repeating the error in option C, this option also uses the incorrect comparison word "fewer" to compare productions of two years. "production" is an uncountable noun, so we cannot use "fewer".
To learn more about countable and uncountable nouns and the appropriate comparison words for them, please read this article .
(E) Incorrect . The use of "fewer" is incorrect, as explained in option D. Also, "that of" is incorrect, as explained in the sentence analysis.