Which of the following can increase a partner's basis in the partnership?

A partner's basis in a partnership is essentially their financial investment in that partnership and can be affected by various factors. When it comes to increasing a partner's basis, one of the key elements is the partner's share of partnership liabilities.

Under the tax code, a partner's basis is increased by their share of liabilities that the partnership incurs, which effectively increases their investment or stake in the partnership. This is because, by being responsible for a portion of the partnership’s debts, the partner has more at risk in the venture, hence raising their basis.

For context, distributions received and withdrawals typically reduce a partner's basis because they represent a return of the partner's investment. Partnership losses also decrease a partner's basis as the losses are passed through to the partners and reduce their equity in the partnership. Therefore, the only factor presented here that can increase a partner's basis is their share of partnership liabilities.