Sandhill Inc. incurred the following costs during the year ended December 31, 2021: Laboratory research aimed at discovery of new knowledge $294000 Costs of testing prototype and design modifications 67000 Quality control during commercial production, including routine testing 264000 of products Construction of research facilities having an estimated useful life of 6 years but no alternative future use 312000 The total amount to be classified and expensed as research and development in 2021 is:______

a. $677000.
b. $937000.
c. $413000.
d. $673000.