The OP's original question has some flaws. Since he is asking the most possible product among the given four, I'd give reasonable mechanism to achieve that product, which would be C. Following is the suggested mechanism:
Late addition: Evidently, lithium diisopropylamide (LDA) has been used to selectively abstract proton from the least steric position among three available acidic hydrogens (irreversible generation of the kinetic enolate). Such a non-nucleophilic, sterically-demanding, strong base will always abstract a proton from the least hindered side. The resultant lithium enolates will avoide Proton transfer at low temperatures in ethereal solvents, so that addition of a second carbonyl group will produce the desired aldol product (Organic Chemistry Portal). For an example for use of lithium dialkyl amide in aldol condensation, see the given reference:
Atsushi Seki, Fusae Ishiwata, Youichi Takizawa, Masatoshi Asami, "Crossed aldol reaction using cross-linked polymer-bound lithium dialkylamide," Tetrahedron 2004, 60(23), 5001-5011 (https://doi.org/10.1016/j.tet.2004.04.026).