Qualified business income (qbi) deduction (lo 4.10)rob operates a small plumbing supplies business as a sole proprietor. in 2018, the plumbing business has gross business income of $421,000 and business expenses of $267,000, including wages paid of $58,000. the business sold some land that had been held for investment generating a long-term capital gain of $15,000. the business has $300,000 of qualified business property in 2018. rob's wife, marie, has wage income of $250,000. they jointly sold stocks in 2018 and generated a long-term capital gain of $13,000. rob and marie have no dependents and in 2018, they take the standard deduction of $24,000.the income threshold for qbi limitations starts at $315,000 for married filing jointly taxpayers. a. what is rob and marie's taxable income before the qbi deduction? $b. what is rob and marie's qbi? $154,000what is rob and marie's qbi deduction? $** give explanation and not just the answer. you! **