Elizabeth's contribution would be expected to be
.. $80,000 * 4/(3 +4) = 45,714.29
The closest answer is the 4th selection, but it doesn't really agree with the conditions of the problem statement.
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If Steve invests the balance after Elizabeth contributes 45,600, the ratio of their contributions will be 43:57, about 0.7544, not 3:4 = 0.7500.