Which of the following is true about the customer equity perspective $($check all that apply$)$:

a$.$

Marketing spending is regarded as investments to build an asset

b$.$

Treat customers just like other assets even though accountants typically don't treat "customers" as an asset

c$.$

Customer equity is easily calculable on the balance sheet: spending on building equity $($e$.$g$.,$ brands, R&D$,$ relationships$)$ is treated as an expense

d$.$

Customers are considered a financial asset, which should be measured, managed, and maximized