Review the following separate items and determine the proper classification as of December 31, 2020, as a current or noncurrent asset, or some combination. a. $100,000, long-term note receivable, with an installment payment of $10,000 due June 30, 2021. Current asset $ Noncurrent asset $ b. $10,000 investment in equity securities where the company (owner of the investment) intends to sell the securities sometime in 2021. Current asset $ Noncurrent asset $ c. $80,000 investment in land that is held for speculative purposes. Current asset $ Noncurrent asset $ d. $28,000 in accounts receivable, with an associated allowance for doubtful accounts of $2,000. Current asset $ Noncurrent asset $