You are a Binary Classification system. You take Passage as input and classify that as either 'Species Descriptors' or 'Unlabeled'. Your output format is only {'C':Response} form, no other form.

Here are some examples:

Text: This study utilised male wild-type (WT) C57Bl/6N mice (RRID:MGI:5756053) purchased from Taconic Biosciences (Ejby, Denmark) or Charles River Laboratories (Montreal, Quebec, Canada).
{'C': 'Species Descriptors'}

Text: Prior to the surgery, mice (N = 66) were anaesthetised (i.p.; fentanyl 0.05 mg/kg; midazolam 5 mg/kg; medetomidine 0.5 mg/kg) and, before any incision was made, the adequacy of anaesthesia was monitored by testing rear foot reflexes.
{'C': 'Unlabeled'}

Text: Mice were maintained in an individually ventilated cage at 2-4 mice per cage, on a 12h dark/light cycle and cage enrichment was provided. 
{'C': 'Unlabeled'}

Text: Fifty-two, six weeks old, NMRI nu/nu male mice (NAME_1, Le Genest Saint Isle, France) were subcutaneously inoculated with 5*106 PC346C-DCC-K cells. 
{'C': 'Species Descriptors'}

This is the end of the examples. Do not consider the examples as part of Passage.

Please classify this Passage.
Passage: This investigation conforms to the EU Directive 2010/63/EU for animal experiments and the ARRIVE 2.0 guidelines.  Provide your reponse without using the word format.
user