16-30: Spencer, CPA, has been engaged to audit the fair value measurements of Christensen & Son, a high-tech company in the Midwest. During the audit, Spencer must obtain evidence that management of Christensen & Son has appropriately valued the following two accounts:

1.	Available-for-Sale Stock Portfolio, containing investments in Fortune 100 company stocks.
2.	Stock compensation expense related to stock options granted to Christensen's employees as valued by the Black-Scholes option-pricing model. Christensen's stock is largely held by the owners and neither the company's stock nor the related stock options are actively traded.

Required:

For each account, complete the following:

a.	Identify the fair value inputs to the value of each account.
b.	Identify the valuation levels for each of the identified inputs as well as the account as a whole (i.e., Level 1, Level 2, or Level 3).
c.	Create a summary audit plan, by account, for how Spencer can obtain assurance regarding the fair value of each of the inputs.