Please answer the given financial question based on the context.
Context: |||Year Ended December 31,||
||2019|2018|2017|
|Cost of revenues|2,193|2,315|2,000|
|Sales and marketing|6,812|6,596|6,621|
|Research and development|4,804|6,137|7,949|
|General and administrative|18,328|16,338|15,682|
|Total stock-based compensation expense|32,137|31,386|32,252|
Stock-based Compensation Expense
The following table sets forth the total stock-based compensation expense resulting from stock options, RSUs, and ESPP included in the Company’s consolidated statements of operations (in thousands):
During the years ended December 31, 2019, 2018, and 2017 the Company capitalized stock-based compensation cost of $0.5 million, $0.1 million, and $0.3 million, respectively, in projects in process as part of property and equipment, net on the accompanying consolidated balance sheets.
As of December 31, 2019, there was $60.3 million unrecognized stock-based compensation expense of which $13.9 million is related to stock options and ESPP and $46.4 million is related to RSUs. The total unrecognized stock-based compensation expense related to stock options and ESPP as of December 31, 2019 will be amortized over a weighted-average period of 2.87 years. The total unrecognized stock-based compensation expense related to RSUs as of December 31, 2019 will be amortized over a weighted-average period of 2.69 years.
Question: What do stock-based compensation expense result from?
Answer:
expense resulting from stock options, RSUs, and ESPP