It seems that it is up to the manufacturer or operator to decide (cf 8168 below). From the Airbus side, it is considered as class C (cf Airbus Airport Planning Manual). The question was asked recently in one monthly quiz of A320Expert with reference to the documentation.
Pan OPS8168 Volume II
1.8.2 The criteria taken into consideration for the classification of aeroplanes by categories is the indicated airspeed at threshold (Vat) which is equal to the stall speed Vso multiplied by 1.3 or stall speed Vs1g multiplied by 1.23 in the landing configuration at the maximum certificated landing mass. If both Vso and Vs1g are available, the higher resulting Vat shall be used.
1.8.3 The landing configuration which is to be taken into consideration shall be defined by the operator or by the aeroplane manufacturer.
1.8.4 Aircraft categories will be referred to throughout this document by their letter designations as follows: Category A — less than 169 km/h (91 kt) indicated airspeed (IAS) Category B — 169 km/h (91 kt) or more but less than 224 km/h (121 kt) IAS Category C — 224 km/h (121 kt) or more but less than 261 km/h (141 kt) IAS Category D — 261 km/h (141 kt) or more but less than 307 km/h (166 kt) IAS Category E — 307 km/h (166 kt) or more but less than 391 km/h (211 kt) IAS Category H — see 1.8.8, “Helicopters”.
Last edited by Aerazur; 12th Apr 2021 at 20:03.