In CONTRAST to sexual reproduction in plants, sexually-reproducing fungi:

a. generate genetic variation during meiosis
b. do not transition from haploid to diploid stages
c. produce spores from haploid mycelium
d. separate the two stages of fusion between parent cells and parent DNA

Option D,  separate the two stages of fusion between parent cells and parent DNA

Explanation:

The stage of sexual reproduction of fungi consists of three stages -  

A) plasmogamy

B) Karyogamy, and  

C) Meiosis  

In plasmogamy, two protoplasts fuses to bring closer two haploid nuclei. The two haploid nuclei fuse to form a diploid nucleus in karyogamy. After karyogamy meiosis occurs that leads to division of chromosome number in a way so that each cell contains one set of chromosome number.  

So , in nut shell in one stage the parent cell i.e protoplast fuses and in the other stage parent DNA fuses.  

answer; lags, push the econ below the natural level of output;