Which of the following, when paid to manage investments that produce taxable income, is a deductible expense?

The cost of investment advice is indeed a deductible expense when it comes to managing investments that generate taxable income. This is grounded in tax regulations that allow for the deduction of expenses that are directly associated with the production of taxable income.

Investment advice is considered a necessary and ordinary expense in the context of managing an investment portfolio. This expense is intended to enhance the taxpayer’s ability to make informed decisions about their investments, thus aligning with the IRS's criteria for deductibility. When a tax filer pays for professional advice to improve their investment performance or to manage their taxable income effectively, this cost can be categorized as an investment management expense that directly supports the goal of generating taxable income.

In contrast, commissions paid on sales of stock are not deductible as expenses; instead, they are added to the cost basis of the stock sold. Similarly, the cost of attending an investment seminar and traveling to a shareholders' meeting, while potentially beneficial, do not directly relate to the management of investments generating taxable income in a way that makes them deductible. They do not meet the standard IRS requirements for ordinary and necessary business expenses under the circumstances described for this question.