Advances in the production of high-temperature superconductors are expected to increase the viability of so-called "maglev" trains that float on magnetic fields.
A.
Advances in the production of high-temperature superconductors
are expected to.
Advances is Plural.B. It is expected that advances in the production of high-temperature superconductors
should. 'should' is used to recommendation. It is illogical here.
C. It is expected that advances in the production of high-temperature superconductors would. we need to use 'will' instead of 'would' as we are expecting in the present.
D. Advances in the production of high-temperature superconductors are expected for them to .
Illogical. Advances in the production of high-temperature superconductors are expected for superconductors
E. Advances in the production of high-temperature superconductors
is expected to.
advances is plural.