Complex sentence: The CMBR has a thermal black body spectrum at a temperature of K, which peaks at the microwave range frequency of 160.2 GHz, corresponding to a 1.873 mm wavelength.
Split into simpler sentences: The CMBR has a thermal black body spectrum at a temperature of K,. On definition (a), the peak spectral density occurs at a frequency of 160.2 GHz, corresponding to a 1.873 mm wavelength.